The 316 is with ArtousteIII engine and the 319 with Astazou engine.
AFAIK the Artouste has double TBO time then the Astazou.
It's not bery comfortable but good for working and very spacious. I have only about 100 hours on AL III (316) but I liked to do external load.
The Lama (same dynamic components) is even better for work.
Always happy landings
Spencer17